Dysbiosis of the Fecal Microbiota in Cattle Infected with Mycobacterium avium subsp. paratuberculosis.

Johne's disease (JD) is a chronic, intestinal infection of cattle, caused by Mycobacterium avium subsp. paratuberculosis (MAP). It results in granulomatous inflammation of the intestinal lining, leading to malabsorption, diarrhea, and weight loss.

Successful Treatment of Dry Mouth and Dry Eye Symptoms in Sjögren's Syndrome Patients With Oral Pilocarpine: A Randomized, Placebo-Controlled, Dose-Adjustment Study.

Background: : Sjögren's syndrome is characterized by the presence of xerostomia and/or xerophthalmia. Pilocarpine, a muscarinic cholinergic agonist, has been proven to be efficacious in treating radiation-induced xerostomia (up to 30 mg/day) and symptoms of dry mouth in Sjögren's patients (up to 20 mg/day).

Objective: : To compare the safety and efficacy of oral pilocarpine (dose-adjusted) versus placebo in the treatment of dry eye and dry mouth symptoms in Sjögren's syndrome at 6 and 12 weeks.

Pharmacokinetics of palonosetron in combination with aprepitant in healthy volunteers.

Background: Palonosetron is a second-generation 5-HT(3) receptor antagonist with a prolonged duration of action and higher receptor binding affinity than first-generation agents (ondansetron, granisetron, and dolasetron). Aprepitant is a selective antagonist of substance P/neurokinin 1 that augments the benefit of 5-HT(3) receptor antagonists in the prevention of chemotherapy-induced nausea and vomiting.

Methods: This randomized, open-label, two-way, crossover trial was designed to evaluate the effect of oral aprepitant on the pharmacokinetics and safety of a single intravenous (IV) dose of palonosetron in 12 healthy subjects.

Evaluation of safety and pharmacokinetics of consecutive multiple-day dosing of palonosetron in healthy subjects.

This study evaluated the safety and pharmacokinetics of consecutive multiple-day dosing of palonosetron. Sixteen healthy subjects received an intravenous bolus dose of palonosetron 0.25 mg (n = 12) or placebo (n = 4) daily for 3 consecutive days.

Mutans streptococci in xerostomic cancer patients after pilocarpine therapy: a pilot study.

Objectives: Opiod- and/or radiation-induced xerostomia in cancer patients is frequently associated with elevated levels of cariogenic mutans streptococci (MS).

Study Design: In a single-center, single blind 8-week clinical trial at The University of Texas M. D.

There is communication between all four Ca(2+)-bindings sites of calcineurin B.

We have used site-directed mutagenesis, flow dialysis, and Fourier transform infrared (FTIR) spectroscopy to study Ca(2+)-binding to the regulatory component of calcineurin. Single Glu-Gln(E --> Q) mutations were used to inactivate each of the four Ca(2+)-binding sites of CnB in turn, generating mutants Q1, Q2, Q3, and Q4, with the number indicating which Ca(2+) site is inactivated. The binding data derived from flow dialysis reveal two pairs of sites in the wild-type protein, one pair with very high affinity and the other with lower affinity Ca(2+)-binding sites.

Functional dynamics of the hydrophobic cleft in the N-domain of calmodulin.

Molecular dynamics studies of the N-domain (amino acids 1-77; CaM(1-77)) of Ca2+-loaded calmodulin (CaM) show that a solvent exposed hydrophobic cleft in the crystal structure of CaM exhibits transitions from an exposed (open) to a buried (closed) state over a time scale of nanoseconds. As a consequence of burying the hydrophobic cleft, the R(g) of the protein is reduced by 1.5 A.

Pharmacokinetics of pilocarpine in subjects with varying degrees of renal function.

Data from three separate single-center studies were combined to assess the pharmacokinetics of orally administered pilocarpine. Pilocarpine concentration-time data were used to generate a data set including 42 subjects (34 males, 8 females) with varying degrees of renal function (average of two estimated creatinine clearance rates of 10 to 112 mL/min). Age ranged from 19 to 88 years.

Activation of myosin light chain kinase requires translocation of bound calmodulin.

A novel translocation step is inferred from structural studies of the interactions between the intracellular calcium receptor protein calmodulin (CaM) and one of its regulatory targets. A mutant of CaM missing residues 2-8 (DeltaNCaM) binds skeletal muscle myosin light chain kinase with high affinity but fails to activate catalysis. Small angle x-ray scattering data reveal that DeltaNCaM occupies a position near the catalytic cleft in its complex with the kinase, whereas the native protein translocates to a position near the C-terminal end of the catalytic core.

Large-scale shape changes in proteins and macromolecular complexes.

Proteins and RNA undergo intricate motions as they carry out functions in biological systems. These motions frequently entail large-scale conformational changes that induce changes in the surface structure, or shape, of a molecule. This review describes the experimental characterization of large-scale shape changes in proteins and macromolecular complexes and the effects of such changes on macromolecular behavior.

A model of troponin-I in complex with troponin-C using hybrid experimental data: the inhibitory region is a beta-hairpin.

We present a model for the skeletal muscle troponin-C (TnC)/troponin-I (TnI) interaction, a critical molecular switch that is responsible for calcium-dependent regulation of the contractile mechanism. Despite concerted efforts by multiple groups for more than a decade, attempts to crystallize troponin-C in complex with troponin-I, or in the ternary troponin-complex, have not yet delivered a high-resolution structure. Many groups have pursued different experimental strategies, such as X-ray crystallography, NMR, small-angle scattering, chemical cross-linking, and fluorescent resonance energy transfer (FRET) to gain insights into the nature of the TnC/TnI interaction.

Calmodulin remains extended upon binding to smooth muscle caldesmon: a combined small-angle scattering and fourier transform infrared spectroscopy study.

We show that calmodulin (CaM) has an extended conformation in its complexes with sequences from the smooth muscle thin filament protein caldesmon (CaD) by using small-angle X-ray and neutron scattering with contrast variation. The CaD sequences used in these experiments were a C-terminal fragment, 22kCaD, and a smaller peptide sequence within this fragment, MG56C. Each of these sequences contains the CaM-binding sites A and B previously shown to interact with the C- and N-terminal lobes of CaM, respectively [Wang et al.

X-Rays from the Highly Polarized Broad Absorption Line QSO CSO 755.

We present results from a BeppoSAX observation of the broad absorption line (BAL) QSO CSO 755, which was observed as part of our program to investigate the X-ray properties of highly polarized BAL QSOs. CSO 755 is clearly detected by the BeppoSAX Medium-Energy Concentrator Spectrometers, making it the highest redshift (z=2.88) and most optically luminous (MV=-27.

Global conformational changes control the reactivity of methane monooxygenase.

We present here X-ray scattering data that yield new structural information on the multicomponent enzyme methane monooxygenase and its components: a hydroxylase dimer, and two copies each of a reductase and regulatory protein B. Upon formation of the enzyme complex, the hydroxylase undergoes a dramatic conformational change that is observed in the scattering data as a fundamental change in shape of the scattering particle such that one dimension is narrowed (by 25% or 24 A) while the longest dimension increases (by 20% or 25 A). These changes also are reflected in a 13% increase in radius of gyration upon complex formation.

Heterologous expression of alkene monooxygenase from Rhodococcus rhodochrous B-276.

Alkene monooxygenase (AMO) from Rhodococcus rhodochrous (formerly Nocardia corallina) B-276 is a three-component enzyme system encoded by the four-gene operon amoABCD. AMO catalyses the stereoselective epoxygenation of aliphatic alkenes, yielding primarily R enantiomers. The presumed site of alkene oxygenation is a dinuclear iron centre similar to that in the soluble methane monooxygenases of methanotrophic bacteria, to which AMO exhibits a significant degree of amino acid sequence identity.

Electron transfer reactions in the alkene mono-oxygenase complex from Nocardia corallina B-276.

Nocardia corallina B-276 possesses a multi-component enzyme, alkene mono-oxygenase (AMO), that catalyses the stereoselective epoxygenation of alkenes. The reductase component of this system has been shown by EPR and fluorescence spectroscopy to contain two prosthetic groups, an FAD centre and a [2Fe-2S] cluster. The role of these centres in the epoxygenation reaction was determined by midpoint potential measurements and electron transfer kinetics.

Pilocarpine tablets for the treatment of dry mouth and dry eye symptoms in patients with Sjögren syndrome: a randomized, placebo-controlled, fixed-dose, multicenter trial. P92-01 Study Group.

Background: Patients with Sjögren syndrome (SS) experience slowly progressive infiltration of lacrimal and salivary glands by mononuclear cells. This leads to diminished secretions, with resultant symptoms of xerostomia and xerophthalmia. Although pilocarpine hydrochloride tablets are currently indicated for the treatment of radiation-induced xerostomia, their effects on dry mouth or dry eyes in patients with SS are unclear.

Neutron and X-ray solution scattering provide insights into biomolecular structure and function.

Neutron and X-ray small-angle scattering techniques have made significant advances in their applications in structural molecular biology. They have become important tools for studying the structural basis for biomolecular function, revealing details of protein and DNA structure, as well as functionally important conformational flexibility and interactions. More powerful neutron and X-ray sources are now available which enable faster data acquisition on lower concentration samples, as well as time-resolved studies in the case of synchrotron sources.

Sequence-alignment modelling and molecular docking studies of the epoxygenase component of alkene monooxygenase from Nocardia corallina B-276.

Whole cells of Nocardia corallina B-276 catalyse the stereoselective epoxygenation of alkenes to chiral epoxides. The bacterium expresses an enzyme, alkene monooxygenase, which catalyses the epoxygenation reaction stereoselectively. The enzyme consists of a terminal oxygenase (epoxygenase), an NADH-dependent reductase (reductase) and a regulatory component (coupling protein).

Alkene monooxygenase from Nocardia corallina B-276 is a member of the class of dinuclear iron proteins capable of stereospecific epoxygenation reactions.

Nocardia corallina B-276 possesses a constitutive multi-component alkene monooxygenase which catalyses the epoxidation of terminal and sub-terminal alkenes. The epoxygenase component of this system has been purified with an overall yield of 35%. The electron paramagnetic resonance spectrum of the oxidised protein has a weak signal at g = 4.

Oral pilocarpine for radiation-induced xerostomia: integrated efficacy and safety results from two prospective randomized clinical trials.

Purpose: Pilocarpine hydrochloride administered in either a fixed-dose or in a dose-titration protocol three times a day for 12 weeks was evaluated for its ability to relieve symptoms of postradiation xerostomia and to improve saliva production. The studies were randomized, double-blind, placebo-controlled, multicenter clinical trials. A total of 369 patients who had received at least 40 Gy of radiation to the head and neck with clinically significant xerostomia were enrolled in the two studies.

Oral pilocarpine for post-irradiation xerostomia in patients with head and neck cancer.

Background And Methods: We evaluated pilocarpine hydrochloride for the treatment of radiation-induced xerostomia, a common complication of irradiation of the head and neck. A prospective, randomized, double-blind, placebo-controlled trial was undertaken to test the safety and efficacy of pilocarpine, particularly in reversing the decrease in the production of saliva and other manifestations of xerostomia. Patients received either placebo or pilocarpine (5 mg or 10 mg orally three times a day) for 12 weeks and were evaluated at base line and every 4 weeks.

A multicenter, randomized, double-blind, placebo-controlled, dose-titration study of oral pilocarpine for treatment of radiation-induced xerostomia in head and neck cancer patients.

Purpose: To determine the efficacy and safety of pilocarpine hydrochloride for symptomatic relief of postradiation xerostomia symptoms and for saliva production in patients with head and neck cancer.

Patients And Methods: One hundred sixty-two head and neck cancer patients who had received at least 40 Gy of radiation (117 patients had received > 60 Gy) with clinically significant xerostomia were enrolled onto a randomized, double-blind, placebo-controlled, multi-center clinical investigation. Patients received 2.